The adjusted global anti-phospholipid syndrome score as predictor of damage accrual measured by damage index for APS. A longitudinal study

Objective: To analyse the association between the average ‘adjusted’ Global APS Score (aGAPSS) over time, as a surrogate of disease activity, and change in Damage Index for APS (DIAPS) during follow-up in patients with thrombotic and non-thrombotic APS. Methods: Two hundred APS patients (138 primary, 62 associated to other autoimmune diseases) were included. DIAPS change was calculated as the difference between basal DIAPS and DIAPS at the end of follow-up. The aGAPSS was calculated for each patient at baseline and on a yearly basis for up to 6 years (minimum 3 years). The average score per patient was computed and considered the reference aGAPSS. Linear regression models were designed to analyse the association between mean aGAPSS and DIAPS change. Moreover, factors associated to high (increase of DIAPS  1 during follow-up) vs low (increase of DIAPS <1 during follow-up) damage accrual were assessed. Results: A higher mean aGAPSS value was associated to a DIAPS increase during follow-up (b¼0.04, P<0.001) in the multivariate analysis. Higher mean aGAPSS values were found in patients with a DIAPS increase  1 during follow-up compared with patients with an increase of <1 point [9.22 (95% CI 7.58, 10.86) vs 6.72 (95% CI 6.0, 7.43), P¼0.003]. aGAPSS increased the odds a DIAPS increment of  1 point during followup [OR¼1.12 (95% CI 1.04, 1.21), P¼0.003]. Conclusions: Our data support the utility of longitudinal assessing of the aGAPSS score in predicting damage accrual, measured by DIAPS, in APS.